Direct measurement of reaction kinetics for the decomposition of ultrathin oxide on Si(001) using scanning tunneling microscopy

Abstract

The spatially inhomogeneous thermal decomposition of monolayer thick oxide films on Si(001) has been investigated. After partial desorption, uniformly distributed voids are formed in the oxide layer. Analysis of the evolution in the void area distribution with extent of desorption suggests that the rate determining step in void growth is the creation of a diffusing Si monomer within the void. This explains the unexpected substantial rearrangement of the Si substrate upon desorption of a single monolayer of oxygen.